MIAMI – The Consumer Price Index is supposed to measure inflation, but whose inflation rate are we talking about?

“Those of us who drive big SUVs, have kids in college and are going to stay in a hotel this summer, inflation is probably double the 3 percent top-line CPI,” Mark Zandi, the chief economist at Economy.com, said in a telephone interview.

“Have you been talking to my mother?” Carl Tannenbaum, the chief economist for LaSalle Bank in Chicago, joked in a telephone interview. “She complains that her son the economist keeps telling her there’s low inflation, but …”

On Tuesday, the Bureau of Labor Statistics reported that consumer prices – driven by $2-a-gallon gasoline and rising food prices – increased in May at the fastest pace in more than three years.

The monthly inflation indicator rose 0.6 percent, while the year-over-year increase was at 3.1 percent.

All the same, the so-called “core” rate of inflation, which does not include the volatile prices for food or energy, rose by what economists consider to be a tame 0.2 percent.

“I don’t know why they say it’s a low inflation rate when the things you absolutely need tend to be the ones that fluctuate,” Marlys Harris, editor of Consumer Reports Money Adviser, said in a telephone interview. “I mean, how is fuel not core to your being unless you live maybe in New York City and walk to work?”

Inflation varies depending upon the region, with age, and with one’s demographic situation. Baby boomers, Zandi says, probably are especially harmed by today’s individual goods and services that are going up in price.

For those with young children, the CPI report contained something many already know: The price of milk has risen at the fastest pace since World War II price controls were lifted in the summer of 1946.

Fresh whole milk prices jumped 14.7 percent, primarily due to lower milk production and smaller herds, the Bureau of Labor Statistics says.

Also hitting families hard: the average 13 percent increase last year in the cost of the employee contribution to health insurance premiums, according to a survey from the Kaiser Family Foundation.

Brace yourself, too, if one of the kids just graduated from high school.

The bill for public college tuition for the coming school year is up 14.1 percent from last year, to $4,694, says the College Board.

“Some items that people purchase are very noticeably higher,” said John M. Godfrey, chief economist at Florida Economic Associates in Jacksonville. “But there are other things that people don’t tend to notice.”

He cites cellphone service as more affordable than in the past. And, if you are in the market for a car or truck, new-car prices are down 0.5 percent in the last year, while used-car and truck prices plummeted 11 percent in the last 12 months, the Bureau of Labor Statistics says.

Why do people get so worked up over inflation?

“People’s perceptions about inflation are very, very important as they think about what to ask their boss for a raise or what is a fair rate of return on their investments,” Tannenbaum said.

Labor prices are a key element of inflation. And for retirees, Tannenbaum said, the expectation of rising inflation eventually leads people to demand better returns from Treasury bonds or certificates of deposit. Higher inflation tends to result in higher interest rates.

At least in the short term, the outlook for prices is to begin moderating.

“If history is any guide, temporary things such as energy and food prices will not continue to go up,” Zandi said. “Three to six months from now, we should all be feeling a bit better.”